I’ve been using Ardour since version 2.0 and was quite confident I knew everything about JACK, rtprio and things.
I had a big time gap in audio production (around 5 years) and now I find myself not being able to start ardour - neither a new session nor open an old one. This is the same notebook, no reinstalls (however all recent updates are here).
I’m able to start jack and I’m able to run a bunch of test jack apps: qjackctl, calf plugin host with organ instrument, jack keyboard. I can patch my stack the way I want to my RME Fireface UFX II and I hear organ playing in my headphones. When I start Jack, my pipewire gets out of the way and switches to Jack sink.
I conclude that Jack works.
When I start ardour it refuses to see the running jack server and wants to create a new one and comes back with the errors:
—ERROR: JACK: Cannot create thread res = 1
ERROR: JACK: JackClient::AcquireSelfRealTime error
ERROR: JACK: Cannot use real-time scheduling (RR/5) (1: Operation not permitted)
I can’t understand what I can do to run Ardour now.
Can you copy and paste the startup messages from jackd and from Ardour? Perhaps that will give a clue.
Did your pipewire installation install the pipewire-jack module by chance? If so there could be conflicts between which libjack.so is being loaded by Ardour.
I managed to solve it. I tracked it down to the issue described here Cgroups · jackaudio/jackaudio.github.com Wiki · GitHub
I couldn’t achieve the result using the libcgroup config provided there, but since I run Gentoo - recompiling a kernel is not a big deal for me. I have removed CONFIG_RT_GROUP_SCHED and jack/ardour/mixbus started to work ok.
Just curious, but do you have any Ardour 2 projects you wish to migrate to Ardour 8/9?
If so, just note that certain things will be lost/changed in that process, namely pan settings or any pan automation you once had. ((…Although I did develop a Lua script to salvage pan automation from Ardour 2 projects, if anyone needs it. ))
))